I wouldn't go with an SG special that is for sure. The low end gibsons are not that great. An epi G400 is a nice buy and cheaper too, so you could get a nice amp upgrade as well. A gretsch electromatic pro jet(solid body since I don't know if you would be open to a semihollow) is a good guitar too, for only about 400 dollars.

I'd hunt around for one of the rare, well built Epiphone LP Customs, then I'd use the spare money left over to upgrade the pickups, bridge, tuners, nut and pots. Obviously, re-do all the wiring too at the same time.

Or, I'd try and see if I could get a second hand mid-90's Gibson Studio. I wouldn't get one of the new ones again, but the early and mid-90's ones were superb, and a used one should be fairly cheap.

EDIT:Or actually, instead of the Gibson Studio, I'd go for the new ESP SA-2 Richie Sambora signature guitar, and use the left over couple of hundred to upgrade the pickups from the standard ESP generic pickups to Gibson BurstBucker #2 and #3.

Get rid of that **** gibson immediately. Its what, the cheapest gibson? Meaning basically that it is made like total crap, but they still charge you so much because its Gibson. I dont even like Hellraisers but I mean, come on. Its such a superior guitar to that POS gibson.